1. Field of the Invention
The subject application relates in general to an antenna and a hand-held electronic device using the same, and more particularly to a multi-loop antenna structure and a hand-held electronic device using the same.
2. Description of the Related Art
Referring to FIG. 1, a generally known loop antenna is shown. The generally known loop antenna 10 includes a feeding point 110, a grounding point 120 and a symmetric radiating body 130. There is a complete loop between the feeding point 110, the grounding point 120 and radiating body 130. That is, the current flowing into the feeding point 110 equals the current flowing out of the grounding point 120, therefore the generally known loop antenna 10 is also called balance antenna. As the generally known loop antenna 10 is big in size and the design of the mobile phone is directed towards slimness, lightweight and compactness, the generally known loop antenna 10 is not widely used in the mobile phone.
Referring to FIG. 2, a generally known open end type antenna is shown. The open end type antenna 20 includes a feeding point 210, a grounding point 220 and a radiating body 230. The loop between the feeding point 210, the grounding point 220 and the radiating body 230 is not a complete loop. The current flowing into the feeding point 210 does not equal the current flowing out of the grounding point 220, therefore the open end type antenna 20 is also called unbalance antenna. As the open end type antenna 20 is small in size, most of the conventional mobile phones adopt the open end type antenna 20 as a medium in wireless communication.
Referring to FIG. 3, a distribution diagram of frequency band of a wireless communication system is shown. Along with the advance in electronic technology, many wireless communication systems, such as the Bluetooth and wireless network (BT/WIFI), the Global System for Mobile Communications (GSM), the Global Positioning System (GPS) and the Digital Communication System (DCS)/the Personal Communication Services (PCS)/the Universal Mobile Telecommunications System (UMTS) are provided. As the frequency bands of these wireless communication system are not the same, if the mobile phone would like to support the abovementioned wireless communication systems, at least three antennas are needed to cover the Bluetooth and wireless network (BT/WIFI) frequency band, the GPS frequency band, the GSM frequency band and the DCS/PCS/UMTS frequency band at the same time.